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Vision Health: The AREDS Study

Ensure that your vision stays in top form.

 "The eye is the lamp of the body. If your eyes are good, your whole body will be full of light.  But if your eyes are bad, your whole body will be full of darkness. If then the light within you is darkness, how great is that darkness!”

Maintaining eye health with age is critical for preserving your quality of life. Having ones vision impaired can often have dire latent effects on ones health. Macular degeneration affects 1.75 million Americans and is a leading cause of blindness in the U.S. in individuals over the age of 60.

Age-related macular degeneration (AMD) is characterized by loss of central vision caused by deposits of white or yellow cells (called drusen) in the macula. Wet AMD is less common, but results in more severe vision loss caused by neovascularization in the retina. The dry form of AMD is less severe, presents gradually due to atrophy of the macula and retinal pigment epithelium.

Cataract affects nearly 22 million Americans age 40 and older and is characterized by opacities of the lens. By age 80, more than half of all Americans will have a cataract.

In 1992, researchers began conducting a long-term, multicenter, prospective study to assess the clinical course, prognosis and risk factors of both AMD and cataract. The researchers evaluated 4,757 individuals between 55 and 80 years of age every six months for approximately seven years. Researchers collected data regarding potential risk factors, comorbid conditions, current and past medication and hormone use and nutrient intake. Investigators conducted telephone 24-hour dietary recall interviews and evaluated the subjects for eye health, measuring changes in visual acuity, photographically documenting changes in macula or lens status and assessing self-reported visual function.

The results of AREDS are detailed in numerous studies, with the initial research published in October 2001. The AMD clinical trial included 3,640 subjects with extensive small drusen, intermediate drusen, large drusen, noncentral geographic atrophy, pigment abnormalities or advanced AMD or vision loss due to AMD. The researchers randomized subjects to receive daily supplements containing:

(1) antioxidants including 500 mg vitamin C, 400 IU vitamin E and 15 mg beta carotene,

(2) minerals including 80 mg zinc and 2 mg copper,

(3) antioxidants plus zinc or

(4) placebo.

The investigators followed the subjects for an average of 6.3 years, assessing progression to or treatment for advanced AMD and changes in visual acuity.

Compared to the placebo group, the antioxidant plus zinc group experienced a 28 percent decrease in the likelihood of developing advanced AMD. The subjects in the zinc plus copper group showed a 25 percent decrease in the likelihood of developing AMD, and the antioxidant alone group demonstrated a 20 percent decrease in the likelihood of developing AMD compared to the placebo group.

When excluding the subjects with a lower risk of developing AMD, the results were even more significant. The antioxidant plus zinc group showed a 34 percent decrease in the likelihood of developing advanced AMD, the zinc plus copper group showed a 29 percent decrease and the antioxidant group showed a 24 percent decrease. Furthermore, the researchers found that only the antioxidant plus zinc group showed a statistically significant reduction in rates of at least moderate visual acuity loss.

AREDS also investigated the relationship between the dietary carotenoids lutein/zeaxanthin, vitamin A, alpha-tocopherol and vitamin C and the development of AMD, the results of which were published in September 2007. This arm of the study included 4,519 subjects between 60 to 80 years of age with varying severity of AMD or only small amounts of drusen to serve as the control group.

The subjects completed a food frequency questionnaire to determine nutrient intake. Higher dietary intake of lutein/zeaxanthin correlated with a decreased likelihood of having neovascular AMD, end-stage dry macular degeneration (also called geographic atrophy) and large or extensive intermediate drusen. More specifically, the researchers showed that the subjects with the highest intake of lutein/zeaxanthin had a 35 percent decrease in the likelihood of developing neovascular AMD, a 55 percent decrease in geographic atrophy and a 27 percent decrease in large or extensive intermediate drusen compared to the subjects with the lowest intake.

The AREDS group published several studies investigating the role omega-3 fatty acids play in people with AMD. In May 2007, the researchers published a study investigating lipid intake and the development of AMD in 4,519 subjects between 60 and 80 years of age.

The subjects completed a food-frequency questionnaire and were evaluated for drusen deposits. Higher dietary total omega-3 fatty acid intake, docosahexaenoic acid (DHA) and total fish intake was inversely associated with the development of neovascular AMD. In fact, the subjects with the highest intake of DHA had a 46 percent decrease in the likelihood of developing neovascular AMD compared to the subjects with the lowest intake. Additionally, dietary arachidonic acid intake (an omega-6 fatty acid) was directly associated with AMD prevalence.

In another AREDS study published in September 2008, researchers evaluated DHA, eicosapentaenoic acid (EPA) and fish intake and the development of AMD and central geographic atrophy. The subjects reporting the highest intake of EPA showed a 56 percent decrease in the likelihood of progressing from bilateral drusen to central geographic atrophy, and those with the highest EPA plus DHA showed a 55 percent decrease compared to the subjects with the lowest intake.8

Other interesting findings from the AREDS study include risk factors for AMD. The researchers found that several factors increase the likelihood of developing AMD or geographic atrophy including cigarette smoking, Caucasian race, greater body mass index, less education, diabetes and some medications.

Physical activity and diet also play a role in the development of AMD. In a study published in April 2011, researchers report that the combination of three healthy behaviors (healthy diet, physical activity and not smoking) was associated with 71 percent lower odds for developing AMD. Eating a healthy diet alone resulted in a 46 percent decrease in the likelihood of developing early AMD. The subjects with the most physical activity had a 54 percent decreased likelihood of early AMD compared to the subjects least physically active.

Additionally, vigorous physical activity such as running significantly impacts AMD risk. A study published in January 2009 demonstrated that the relative risk for AMD decreased by 10 percent per km-per-day increment in running distance.

Vision Protection

To ensure that your vision stays in top form, keep these tips in mind:

  • Exercise at least five days a week for 30 minutes at a time.
  • Reduce red meat consumption.
  • Eat fruits and vegetables high in antioxidants, especially lutein and zeaxanthin.
  • Eat wild, cold-water fish at least two days a week.
  • Supplement with 2,000 IU of vitamin D3.
  • Take an antioxidant-rich vision supplement.
  • Wear sunglasses with UVA/UVB protection.

 

Please visit us at: Innovative Nutrition, 206 Rt. 25A, East Setauket, NY 11733 or, online at: www.vibranthealthcompany.net

This post is contributed by a community member. The views expressed in this blog are those of the author and do not necessarily reflect those of Patch Media Corporation. Everyone is welcome to submit a post to Patch. If you'd like to post a blog, go here to get started.

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